I'm not sure I'd say “covering.” Of the 39 states (plus Washington, DC) in the database, records from three-quarters of them don’t go past 1866. Two states have records as late as 1917 and two have them from 1918, but none has uninterrupted coverage for the entire span.

Ancestry.com does have most of the records available from the National Archives, but I have to admit being a little disappointed when I got to the relatively skimpy list of years.

OK, word quibbles aside. You can get an idea of your ancestor’s financial position if he's in these lists of people and businesses who had to pay early federal taxes. (People who didn't have to pay aren't named.)

Congress created the Bureau of Internal Revenue July 1, 1862, to “provide Internal Revenue to support the Government and to pay interest on the Public Debt”—which at the time primarily consisted of Civil War expenses.

Most Confederate states weren’t taxed until after the war.

A variety of laws over the years determined which goods and services were taxable. People and businesses submitted to their collection district a form showing annual income, articles subject to taxes and the quantity of taxable goods made or sold.

Each district assessor compiled lists of taxpayers living in his division and taxpayers living outside but owning property inside his division—these are the lists in Ancestry.com's collection (originals are on microfilm in record group 58 of the National Archives and Records Administration).

They show taxpayers’ names, locations (sometimes an address), taxable articles and valuations. Then some lucky assessor would take the list around to collect the cash.